Hi, I have a problem. The Car is a Volvo 850 R Turbo Wagon, Auto Air 102,000 Miles. While driving our car the rpm started going up and down, so we stopped at a shop.
They said the throttle body was dirty and needed to be removed so, we did that.
We waited a couple of hours for the car and started home. The car ran a little rough, stopped at a signal the car died and the check engine light came on.
Stopped at another shop (shop/service station)
and they said the air pump was dirty. Removed and cleaned that. The car still ran poor but, we had to get home.
Took to a shop once home and the code was bad map sensor 121 and bad temp sensor. Replaced both sensors plus, the thermostat.
Had the radiator flushed
the car still will not idle smells rich? Like gas and will stumble and die out.
When the car is warm it will idle most of the time but will stumble and sometimes die out.
The code still states a bad MAP sensor code 121!!!
The code has been reset (many times) and comes right back.

Here is a list of all we have done to repair fix the car any help or suggestions would be appreciated as we have spent $1500.00 and it is not fixed!
Thanks in advanced for your time to look at this

Cleaned throttle body (removed)
Cleaned the EGR valve (removed)
Cleaned the Idle sensor (removed)
Sealed the Vacuum Leak in Vacuum tower (removed and siliconed)
Replaced the Vacuum hoses
New MAP sensor
New Thermostat
New Thermostat Sensor
New Fuel filter
New hose clamps
New plug wires
New cap
New rotor
New spark plugs
New air filter & box cleaned (no blockage)
New gasket throttle body
Cleaned all connections (electric)
Dielectric grease on all connectors

Also to let you know a mechanic told me that there is only one "hot" wire going to the map sensor
I looked and there are 4 wires total going to the map sensor and only one has power even when the car is running.
I dont know if that is right or not.

Thanks again for all your help.

hi,
wow! you certainly have replaced a lot of items so therefore most causes would have been eliminated. the only other suggestions i can make are if the code is for a map sensor then there is either a problem with the vacum connection to the sensor i.e. blockage in the manifold or hole in the vacum tube etc.. OR there could be a wiring problem between the sensor and the ecu ,this could be a short circuit or open circuit etc, you would need a wiring diagram and a multimeter to check this. OR there could be a fault with the ecu that is causing this code to come up.
the ecu on an 850 is very easy to remove and if you have access to a car with a known good ecu you could swap them and check if that is the cause or not.
hope this helps.
steve.

Hi, Thanks for the information. Do you know where to get a wiring diagram?
or where the ecu on the car is?

Thanks again

hi,
the ecu is located in a plastic box near the right front wing next to the strut tower. but if you have an auto trans there will be 2 ecus in there (1 for engine ,1 for trans). the engine ecu is usually the one nearest the engine,
if you email me i can supply a wiring diagram for the engine to you.
however to do the whole fault tracing thing you need to be reasonably competent with a multimeter and electrical circuits,if not then go see a auto electrician and give them the wiring diagram and explain what you want them to do.
if the MAP fault occurs all the time then i would recomend going to see your local volvo dealer and ask if they could try swapping a ecu of another car to eliminate your one,if your ecu is faulty then this would prove it straight away.
good luck.

steve.

Hi, My Email is bryanb@roadtozen.com If you dont mind the diagram would help I think.
Do you think disconnecting the battery and removing the ecu to reset it is necessary?
One person wrote me about doing that.

Thanks again,

Bryan

to send a diagram i first need to know what year 850? is it turbo or non turbo? and the size of the engine.
as regards the disconnecting the battery/ecu.....it wouldnt hurt to try,you only need to disconnect battery though not both and leave disconnected for at least 10 minuits. however a code in the ecu will only cause the check light to come on if the fault is present in the car, so if the work you have allready done had fixed the fault then the light should have allready gone out.

steve.